Optical transceivers are generally installed in electronic communication facilities in modern high-speed communication networks. In order to make flexible the design of an electronic communication facility and less burdensome the maintenance of the same, an optical transceiver is inserted into a corresponding cage that is disposed in the communication facility in a pluggable manner. In order to define the electrical-to-mechanical interface of the optical transceiver and the corresponding cage, different specifications have been provided such as XFP (10 Gigabit Small Form Factor Pluggable) used in 10 GB/s communication rate and QSFP (Quad Small Form-factor Pluggable).
In order to transmit and receive optical signals over multiple channel wavelengths, multi-channel optical transceivers have been widely used in various applications. The types of the multi-channel optical transceivers, for example, include 2×2, 4×4 or 8×8 channels. Specifically, an 8×8 MIMO (Multi-input Multi-output) optical transceiver includes eight transmitters and eight receivers.